Astragalus (plant)
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Astragalus is a large genus of over 3,000 species<ref name=powo>Template:Cite web</ref> of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species.<ref>Template:Cite journal</ref> The genus is native to temperate regions of the Northern Hemisphere. Common names include milkvetch (most species), locoweed (in North America, some species)<ref>Template:Cite web</ref> and goat's-thorn (A. gummifer, A. tragacantha). Some pale-flowered vetches (Vicia spp.) are similar in appearance, but they are more vine-like than Astragalus.
Description
Most species in the genus have pinnately compound leaves.<ref>Template:Cite book</ref> There are annual and perennial species. The flowers are formed in clusters in a raceme, each flower typical of the legume family, with three types of petals: banner, wings, and keel. The calyx is tubular or bell-shaped.<ref name=foc>Template:EFloras</ref><ref>Template:Cite web</ref>
Taxonomy
The genus was formally described in 1753 by Carl Linnaeus in his Species Plantarum.<ref>Template:Cite web</ref>
The name Astragalus is Greek, an old name for this group of plants which were believed to have a positive effect on goat milk production.<ref>Template:Cite book</ref>
Selected species
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Ecology
Astragalus species are used as food plants by the larvae of some Lepidoptera species including many case-bearing moths of the genus Coleophora: C. cartilaginella, C. colutella, C. euryaula, and C. onobrychiella feed exclusively on Astragalus, C. astragalella and C. gallipennella feed exclusively on the species Astragalus glycyphyllos, and C. hippodromica is limited to Astragalus gombo.Template:Cn
Uses
Traditional medicine
Astragalus has been used in traditional Chinese medicine over centuries to treat various disorders, but there is no high-quality evidence that it is effective or safe for any medical purpose.<ref name="nccih16">Template:Cite web</ref><ref>Template:Cite journal</ref>
Phytochemicals and supplements
Extracts of astragalus root include diverse phytochemicals, such as saponins and isoflavone flavonoids, which are purported in traditional practices to increase lactation in nursing mothers.<ref name="dld">Template:Cite journal</ref> There is no valid clinical evidence to indicate such use is effective or safe for the mother or infant.<ref name=dld/> Dietary supplement products containing astragalus extracts may not have been adequately tested for efficacy, safety, purity or consistency.<ref name=dld/> The root extracts of astragalus may be used in soups, teas or sold in capsules.<ref name=nccih16/>
Side effects and toxicology
Although astragalus supplements are generally well tolerated, mild gastrointestinal upset, diarrhea, and allergic reactions may occur.<ref name=nccih16/><ref name=dld/> Because astragalus may affect regulation of blood sugar and blood pressure, it may be risky for people with blood disorders, diabetes, or hypertension to use it as a supplement.<ref name=nccih16/> Astragalus may interact with prescribed drugs that suppress the immune system, such as medications used by people being treated for cancer or recovery from organ transplants.<ref name=nccih16/>
Some astragalus species can be toxic, such as those found in the United States containing the neurotoxin swainsonine, which causes "locoweed" poisoning in animals.<ref name=nccih16/> Some astragalus species may contain high levels of selenium, possibly causing toxicity.<ref name=nccih16/>
Ornamental use
Several species, including A. alpinus (bluish-purple flowers), A. hypoglottis (purple flowers), and A. lotoides, are grown as ornamental plants in gardens.Template:Citation needed
Notes
References
External links
- Astragalus – Genus of vascular plants
- Astragalus – Clinical summary and constituents, MSKCC Memorial Sloan Kettering Cancer Center